Agricultural Science Commons^™

Response Of Contrasting Cocksfoot Varieties To Summer Moisture Availability In A Mediterranean Environment, E. Piano, M. Romani, A. M. Carroni, L. Pecetti

IGC Proceedings (1977-2023)

The responsiveness to water availability in summer and the effect of summer drought were assessed in a Mediterranean environment on both temperate and Mediterranean cocksfoot (Dactylis glomerata L.) materials. Three consecutive evaluation phases were contemplated: i) under rainfed conditions from autumn to spring; ii) under contrasting moisture conditions in the following summer; and iii) under rainfed conditions in the subsequent autumn-spring season to assess the effect of the previous summer treatments. The ability to become summer dormant under conducive conditions, such as in Mediterranean germplasm, proved a plant pre-requisite for survival under drought. All the “summer-active”, temperate varieties did …

Forage Production And Nutritive Value Of Four Promising Sorghum X Sudangrass Hybrid In Korea, S. Seo, J. G. Kim, E. S. Chung, J. K. Lee, S. H. Yoon

IGC Proceedings (1977-2023)

Sorghum x sudangrass hybrid (Sorghum bicolor (L.) Moench) is one of the most important annual grass utilized for supplemental summer forage. There were 14 National Livestock Cooperative Federation (NLCF)’s recommended forage sorghum´sudangrass hybrids in Korea. Among them several hybrids were produced widely, however, they have not been evaluated under same environmental conditions. Therefore, a field experiment was carried out to compare the plant height, forage yield and nutritive value of the NLCF’s recommended cultivars at NLRI, Suwon, Korea in 1995. The four promising cultivars of sorghum´sudangrass hybrid used in this study were P 988, TE-Haygrazer, NC+ 855 (heading type), …

The Effect Of Plant Population On The Yield And Quality Of Annual Rye-Grass, M. E. V. L. Lourenço, P. M. M. Palma

IGC Proceedings (1977-2023)

The primary objectives of this study were to evaluate the effect of three plant population levels (350, 750 and 1150 plants m^-2) on dry matter yield and forage quality (crude protein and dry matter digestibility) of four rye-grass genotypes (Barspectra, Billion, Clipper and Pollanum) used in two harvests (March and May).

The results for dry matter yield means by year, genotype, and harvest were always higher in the second harvest than in the first, and the highest total mean value was reached in the first year (5853 Kg ha^-1). The genotype Billion was the most stable …

High Yielding And Disease Resistant Elephant Grass Suitable For Intensive Smallholder Dairy Farmers In Kenya, A. B. Orodho

IGC Proceedings (1977-2023)

In Kenya, over 80% of milk is produced by the smallholder dairy farmers who mainly practice semi or zero-grazing dairy management system. Scarcity of livestock feed is a great limiting factor in the dairy industry, especially in the small scale farming systems which rely mostly on fodder. Elephantgrass (Pennisetum purpureum) is the major livestock feed and its productivity depends mostly on management practices. The current fodder crops grown by farmers have been developed through systematic research of collection/introductions, screening and evaluation of forages for their suitability as livestock feed. These adopted fodder cultivars are undergoing yield reduction due …

Intake And Digestibility Of Black Locust Foliage Fed To Growing Goat Wethers, L. J. Unruh, J-M. Luginbuhl, J. P. Mueller

IGC Proceedings (1977-2023)

Leaves of Black locust (BL, Robinia pseudoacacia), a native southeastern United States tree species known to contain substantial levels of condensed tannins, were fed to 16, four month old (20.4 kg body weight [BW]) Boer wether goats (Capra hircus hircus) to determine their effects on intake and digestibility. Four diets were stall fed in a randomized complete block design (RCBD) with four replications. Diets included: (1) 100% eastern gamagrass (EGH; Tripsacum dactyloides) hay; (2) 70% EGH and 30% mixture of ground corn (GC; Zea mays) and soybean (Glycine max) meal (SBM); (3) 75% …

Importance Of Considering Rate Of Passage When Determining Energy Content Of Forages For High Producing Animals, Dan J. Undersander, D. K. Combs, Edgard P. Beyer, Marcello T. Rodrigues

IGC Proceedings (1977-2023)

The objective of this study was to determine the effect of higher rates of passage and correspondingly lower rumen retention times on digestion of forages. One hundred and fifty samples of legumes, grasses and grass-legume mixtures were collected from farmer samples submitted to commercial forage testing laboratories and 32 samples of alfalfa at varying maturity were collected from research plots. In vitro digestions were performed for either 24 or 48 hours followed by neutral detergent analysis. Neither acid detergent fiber (ADF) nor neutral detergent fiber (NDF) predicted the standard 48-hour digestion very well (r² = -0.38 and B0.26, respectively). …

Nutritional Quality Of Digitaria Eriantha Steudel. Subsp. Eriantha Cv. Irene, M. J. L. Privitello, R. L. Sager

IGC Proceedings (1977-2023)

Digitaria eriantha is a South African perennial grass, C4 type, that grows during spring and summer with rainfalls higher than 400mm. The aim of this paper was to evaluate its nutritional quality profile: Crude Protein (%CP), True Protein (%TP), Soluble Protein (%SP), Non-Protein Nitrogen (%NPN), Neutral Detergent Fiber (%NDF) and Acid Detergent Fiber (%ADF) in cumulative production cuttings during a species cycle. In-sacco technique was applied to estimate the degradability of dry matter (DM). A simple regression statistics method was applied to relate different nutritional parameters. Digitaria eriantha presents low percentage of CP from flowering and of NPN during its …

Agronomic Potential And Nutritive Value Of Promising Leucaena Species In The Yucatan Peninsula, Luis Ramírez-Avilés, W. O. Cruz, Francisco J. Solorio-Sánchez

IGC Proceedings (1977-2023)

Two experiments were carried out in order to evaluate the agronomic potential, the nutritive value and the tolerance to psyllid (Heteropsilla cubana) of nine Leucaena species. A randomized block design with four repetitions was used. There were significant (P< 0.01) differences on dry matter production (i.e. leaf and twigs yield ). L. collinsii showed the most promising result, which could be related to its high psyllid tolerance. In a second experiment, the preference indices of Leucaena species was assessed with sixteen male pelibuey sheep in a cafeteria trial. There were significant (P< 0.0001) differences among Leucaena species. L. esculenta paniculata was the species most preferred . There was no relationship between chemical composition …

Ramon (Brosimun Alicastrum) Foliage As Supplement For Lactating Dual Purpose Cows, Carlos A. Sandoval-Castro, R. Cetina, I. Pérez, Luis Ramírez-Avilés

IGC Proceedings (1977-2023)

The objective of the present study was to asses the value of ramón (Brosimun alicastrum) foliage as a N-source in replacement of soybean-N in lactating dual purpose cows (Bos indicus x B. taurus). Four lactating cows were used in a latin rectangle design. Ramón was included to replace 0, 33, 66 and 100 % of the soybean-N contained in the supplement. Basal diet was fresh “Taiwán” a cultivar of Elephant grass (Pennisetum purpureum) fed ad libitum. Basal and total dry matter intake, digestibility (total fecal collection), saleable and calf suckled milk yields, and …

Dry Matter Yield, In Vitro Digestibility, Protein And Fiber Composition Of 'Tifton 9' Bahiagrass (Paspalum Notatum) At Six Maturities, J. M. B. Vendramini, C. M. Haddad, Carlos G. S. Pedreira

IGC Proceedings (1977-2023)

The objective of this research was to evaluate dry matter yield, in vitro digestibility, and the concentrations of protein and cell wall components in 'Tifton 9’clipped at six maturities. Herbage was cut at the age of 20, 27, 34, 41, 48 and 55 days. The experimental design was a randomized complete block with six trataments (ages) and four replications. Dry matter yield and acid detergent fiber ranged from 188 g m^-2, to 593 g m^-2 and 386.9 g kg^-1 to 375.1 g kg^-1 respectively, with the cubic regression model having the best fit (P< 0.05). Concentrations of crude protein decreased linearly (P< 0.05) from 121 to 69 g kg^-1. …

In Situ Degradability Of Hand Harvested Or Extrusa Samples Of Tanzania Grass (Panicum Maximum, Jacq.), T. T. Berchielli, A. K. D. Salman, R. N. Silveira, W. V. B. Soares, J. R. Nogueira, S. N. Kronka

IGC Proceedings (1977-2023)

In order to compare the in situ degradability of tanzania grass samples obtained as by extrusa or hand plucked, three ruminal fistulated cows were used in a completely randomized block design with split-plot scheme. Five grams of extrusa or hand harvested grasses were placed in nylon bags rumen incubated during 3, 6, 12, 24, 48, 96 and 120 hours. The degradability of DM, CP, NDF and ADF were, in this sequence, 62.59, 80.88, 50.73 and 46.65%, for hand harvested grass; and 79.53, 90.97, 71.21 and 65.68%, for extrusa. In situ degradability data of hand harvested samples were not reliable.

Herbivore Preference For Afternoon- And Morning-Cut Forages And Adoption Of Cutting Management Strategies, H. F. Mayland, J. C. Burns, D. S. Fisher, Glenn E. Shewmaker, R. Carlstrom, D. S. Cash

IGC Proceedings (1977-2023)

Photosynthesizing forage plants accumulate total nonstructural carbohydrates (TNC) during daylight, but then TNC concentrations are reduced during the night. Afternoon-cut forage (PM) has greater TNC value and thus economic value, than morning-cut (AM). Livestock prefer PM-cut hay and this can be readily demonstrated by offering animals a choice of hays cut in PM and AM. Alfalfa growers in the western United States are readily adopting PM-cutting technology to increase profits.

Near Infra-Red Measurement Of Nonstructural Carbohydrates In Alfalfa Hay, H. F. Mayland, J. C. Burns, D. S. Fisher, Glenn E. Shewmaker

IGC Proceedings (1977-2023)

Recently documented benefits from afternoon versus morning cut forage have encouraged laboratory reporting of total nonstructural carbohydrate (TNC) values as part of forage quality testing. Our objective was to determine if infra-red spectroscopy (NIRS), which is being used in many forage testing labs, could be reliably used to quantify forage sugars in hay samples. We used two alfalfa (Medicago sativa L.) sample populations that were analyzed by wet chemistry for sugars and scanned by NIRS. The first set consisted of field-dried hay samples that were oven dried at 70^oC and the second consisted of fresh, freeze-dried samples. …

Intake And Qualitative Aspects Of Guinea Grass Grazed By Sheep Over Three Different Seasons, Willem A. Van Niekerk

IGC Proceedings (1977-2023)

The objective of this study was to determine the influence of season on intake by sheep as well as certain selected qualitative characteristics of Panicum maximum (cv Gatton) (Guinea grass) at the mature growing stage. The lower DM content of the spring and summer grass (41.6 and 40.2%) did not hamper DOMI (48.1 and 26.7 W^0.75/d), respectively. The N concentration of the spring and summer grass was well within the limit required for optimal rumen microbial production (1.8 - 2.0%). The high cell wall components of the winter grass resulted most probably in a significant lower IVDOM value …

Identification And Quantification Of N-Alkanes In Three Tropical Grasses, T. C. M. Genro, Ê. R. Prates, L. R. L. De S. Thiago, M. Herrero, V. Sabatel

IGC Proceedings (1977-2023)

The main goal of this paper was to quantify the profile of n-alkanes in three tropical grasses. Hand plucking samples to simulate grazing were taking from Brachiaria brizantha cv. Marandu, Panicum maximum cv. Mombaça and Pennisetum purpureum cv. Cameroon. These samples were collected from an experiment established to assess intensive beef production from grasses throughout the year, under rotational grazing. Rotation order through the paddocks remained constant, with 30 days of rest after each grazing bout (16 paddocks, 2 days of grazing). Profiles of n-alkanes were analysed in three separate periods of the year: in the middle of the dry …

Determination Of N-Alkanes At Different Stratum Heights In A Pasture Of Panicum Maximum Cv. Mombaça, T. C. M. Genro, L. R. L. De S. Thiago, Ê. R. Prates, M. Herrero, V. Sabatel

IGC Proceedings (1977-2023)

The aim of this experiment was to determine n-alkane levels in the stem + leaf sheath and leaf blade components of a pasture of Panicum maximum cv. Mombaça, harvested in 20 cm stratified layers. This pasture was under rotational grazing for intensive beef production throughout the year. The grazing system was based on the use of 16 paddocks with a 2-day grazing period followed by a 30-day resting period. Profiles of n-alkanes were determined in samples harvested in three separate periods: in the middle of the dry season (August 97; PERIOD 1), at the beginning of the wet season (November …

Observation Of Bundle Sheath Digestion Of Panicum Maximum Jacq,, B. Lempp, Valéria P. B. Euclides, Maria Da Graça Morais, D. M. Victor

IGC Proceedings (1977-2023)

Cross-sections of available forage and extrusa fractions of leaf blades of Tanzânia-1, Mombaça and Massai grasses were evaluated for anatomic structure and observations of residue of in vitro digestibility. The observations showed greater frequency of scherenchyma girders in leaf blades of cv Massai, compared with order grasses. Tanzânia-1 and Mombaça residues were more susceptible to digestion, while Massai presented more frequently scherenchyma girders associated with less digestible bundle sheath.

A Simple Method For Estimating Alfalfa Fiber Content In The Field, Reuben M. Sulc, K. A. Albrecht, V. N. Owens

IGC Proceedings (1977-2023)

Predictive equations for alfalfa (Medicago sativa L.) quality (PEAQ) based on length of the longest stem and maturity stage of the most mature stem in a sample were developed and validated for estimating neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations in alfalfa. The objective of this research was to validate PEAQ with a simplified maturity scale when estimating fiber content. Alfalfa samples varying in height and maturity were collected throughout the growing season from fields across six states in USA. Observed NDF and ADF values (determined via wet chemistry) were regressed on estimated values. The estimated …

Using Uav Technology Paired With Multispectral Cameras To Assess Crown Rust Epidemics In Oats, Turner A. Graham

LSU Master's Theses

Crown rust, caused by Puccinia cornonata f. sp. avenae, is a common disease of oats (Avena sativa) found virtually everywhere oats are cultivated. This disease has caused yield losses of 10 to 40% worldwide. Early detection is important for effective management. A more recently utilized technology in agriculture is unmanned aerial vehicles (UAVs). UAVs, or drones, equipped with cameras are now being used as a resource to take images of fields to identify pests and other issues that may be occurring. Normalized differentiated vegetative index (NDVI) is a numerical indicator used to determine the vegetative health of …

Effective Growing Degree Days As A Critical Factor For Yield And Qualitative Values Of Timothy In Subarctic Growing Conditions, Oiva Nissinen

IGC Proceedings (1977-2023)

The yield and forage quality of timothy (Phleum pratense L.) leys at different stages of development were studied in 1991-1999 at the Lapland Research Station of the Agricultural Research Centre of Finland in Rovaniemi (66^o35´N). The aim of the study was to determine the optimal time for the first cut with respect to yield and qualitative values. In timothy the first heads were visible on 25 June on average and full heading was seen on 5 July, i.e. some ten days later. During this period the dry matter yield increased from 2769 to 4945 kg/ha, crude protein …